- Mixed nerve.
- Largest of the three divisions of the fifth cranial nerve.
- Made up of two roots:
- A large – sensory root proceeding from the inferior angle of the semilunar ganglion.
- A small motor root which passes beneath the ganglion unites with the sensory root just after it exit foramen ovale.
It exits skull from foramen ovale.
Immediately beneath the base of the skull gives off a recurrent branch (nervous spinosus) and the nerve to the Pterygoideus internus then divides into two trunks an anterior and a posterior
Middle cranial fossa is supplied by maxillary and mandibular nerve.
1. Main trunk
1. Nerve to Medial pterygoid
- Supplies medial pterygoid.
- It also supplies tensor tympani & tensor veli palatini through otic ganglion.
2. Meningeal branch (nervous spinosum)
- Passes through foramen spinosum to supply dura mater of middle cranial fossa.
2. Anterior division
- The anterior and smaller division of the Mandibular nerve receives nearly the whole of the fibers of the motor root of the nerve.
- Nerve to masseter, supplies masseter
- Deep temporal nerve supplies temporalis.
- Nerve to lateral pterygoid supplies lateral pterygoid muscle.
- Buccal nerve, supplies skin over buccinator, mucous membrane of cheek, vestibule of mouth.
3. Posterior division
- The posterior and larger division of the Mandibular nerve sensory but receives a few filaments from the motor root.
1. AURICULAR NERVE:
- It receives postganglionic secretomotor fibres from otic ganglion which supply parotid gland.
- It also supplies TMJ, lateral surface of auricle, & anteroinferior wall of external acoustic meatus.
- It is joined by chorda tympani branch of facial nerve, conveying secretomotor fibres for submandibular gland & taste sensory fibers from anterior two third of tongue.
- It grooves the medial aspect of socket for lower third molar, runs forward over hyoglossus muscle & loops around submandibular duct to reach inferior surface of tongue.
- It supplies mucosa of anterior 2/3 of tongue, floor of mouth & inner gums of lower teeth.
3. INFERIOR ALVEOLAR NERVE:
- Mixed, Largest branch of the Mandibular nerve.
- Descends with the inferior alveolar artery at first beneath the lateral Pterygoid then b/w the sphenomandibular ligament and the ramus of the mandible to the Mandibular foramen.
- Then passes forward in the Mandibular canal beneath the teeth as far as the mental foramen where it divides into two terminal branches incisive and mental.
- Branches of the inferior alveolar nerve are :
- Derived from inferior alveolar just before it enters the mandibular foramen.
- It descends groove on the deep surface of the ramus of the mandible reaching the under surface of the Mylohyoid supplies this muscle and the anterior belly of the Digastric.
- Supply molar and premolar teeth
- Above the alveolar nerve they form an inferior dental plexus.
- Continued onward within the bone and supplies the canine and incisor teeth.
- Emerges at the mental foramen divides beneath the Triangularis muscle into three branches.
- One descends to the skin of the chin.
- Two ascend to the skin and mucous membrane of the lower lip.
- These branches communicate freely with the facial nerve.
- Mandibular nerve exits skull from foramen ovale.
- Middle cranial fossa is supplied by maxillary and mandibular nerve.
- Nervous spinosus (meningeal branch) enters the skull through foramen spinosum.
- Anterior division of mandibular nerve supplies Muscles of mastication, mylohyoid, anterior belly of digastric,medial pterygoid , tensor tympani and tensor veli palatini & Skin and mucous membrane of the cheek
- Anterior division of mandibular nerve have 4 branches Massetric,External Pterygoid, Deep Temporal & Buccinator.
- Lingual nerve runs across the duct of the submandibular gland.
- The branch arising from the main trunk of mandibular nerve is Nerve to medial pterygoid.